I will be using solid subframe bushings on my '68. I just ordered the kit containing the bushngs for all six body mount locations.

I have read though, that the solid bushings were not recommended to use where the radiator core support attachches to the subframe because the transmitted vibration could damage the radiator.

I am just looking for opinions on this. Has anyone actually ever had this happen to them? I have no problem buying rubber mounts for that connection if I need to. I don't want to though, if there is no good reason for it.

I will be using solid subframe bushings on my '68. I just ordered the kit containing the bushngs for all six body mount locations.

I have read though, that the solid bushings were not recommended to use where the radiator core support attachches to the subframe because the transmitted vibration could damage the radiator.

I am just looking for opinions on this. Has anyone actually ever had this happen to them? I have no problem buying rubber mounts for that connection if I need to. I don't want to though, if there is no good reason for it.

Thanks........Dave

Dave, don't know but curious why you want solid mounts or the "good reason for it."

Radiator joint failure is caused by expansion and contraction. The radiator's rubber mounts solve this problem. Vibration of which you speak still gets transmitted to the radiator support through the front end sheetmetal, whether you have solid mounts under the support or not.

I asked this question in the first place because of old posts I have read on the forums where people thought the solid bushings at the core support were a bad idea. I was just trying to see if there were some more current opinions. There are also a bunch of old posts out there from people who felt differently. Many said they have used solid bushings at the core support for years and have never had any radiator problems.

Since the radiator uses rubber mounts, I am going to go ahead and use the solids all the way around.

As to why GM didn't use solid mounts, I am guessing rubber mounts were a compromise to please all drivers. A firm ride that might be acceptable and fun to one us might not have been to the average driver.

The only possible purpose would be an attempt to use the front sheet metal structure to *further stiffen* the subframe... which I would question the effect as well. If solid mounts were used at the rear four attachment points, essentially the rear of the subframe is 'a part of the body structure, leaving only the 'cantilevered flexibility' of the subframe in question (re the suspension geometry). Does the front sheet metal provide additional regidity to the frame structure? I'd guess any impact would be minimal?

The six rubber-cushioned subframe mounts (two at the radiator support, four at the floor pan) on the "F"-body served exactly the same purpose as the twelve rubber-cushioned body mounts on a full-frame "B"-body - to isolate the NVH (Noise, Vibration, and Harshness) of the chassis from the body structure and passenger compartment.